[unix-history] / sys / ufs / dir.h

/*
 * Copyright (c) UNIX System Laboratories, Inc.  All or some portions
 * of this file are derived from material licensed to the
 * University of California by American Telephone and Telegraph Co.
 * or UNIX System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 */
/*
 * Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: @(#)dir.h	7.10 (Berkeley) 3/25/91
 *	$Id: dir.h,v 1.2 1993/10/16 18:17:37 rgrimes Exp $
 */

#ifndef _DIR_H_
#define	_DIR_H_

/*
 * A directory consists of some number of blocks of DIRBLKSIZ
 * bytes, where DIRBLKSIZ is chosen such that it can be transferred
 * to disk in a single atomic operation (e.g. 512 bytes on most machines).
 *
 * Each DIRBLKSIZ byte block contains some number of directory entry
 * structures, which are of variable length.  Each directory entry has
 * a struct direct at the front of it, containing its inode number,
 * the length of the entry, and the length of the name contained in
 * the entry.  These are followed by the name padded to a 4 byte boundary
 * with null bytes.  All names are guaranteed null terminated.
 * The maximum length of a name in a directory is MAXNAMLEN.
 *
 * The macro DIRSIZ(dp) gives the amount of space required to represent
 * a directory entry.  Free space in a directory is represented by
 * entries which have dp->d_reclen > DIRSIZ(dp).  All DIRBLKSIZ bytes
 * in a directory block are claimed by the directory entries.  This
 * usually results in the last entry in a directory having a large
 * dp->d_reclen.  When entries are deleted from a directory, the
 * space is returned to the previous entry in the same directory
 * block by increasing its dp->d_reclen.  If the first entry of
 * a directory block is free, then its dp->d_ino is set to 0.
 * Entries other than the first in a directory do not normally have
 * dp->d_ino set to 0.
 */
#define DIRBLKSIZ	DEV_BSIZE
#define	MAXNAMLEN	255

struct	direct {
	u_long	d_ino;			/* inode number of entry */
	u_short	d_reclen;		/* length of this record */
	u_short	d_namlen;		/* length of string in d_name */
	char	d_name[MAXNAMLEN + 1];	/* name with length <= MAXNAMLEN */
};

/*
 * The DIRSIZ macro gives the minimum record length which will hold
 * the directory entry.  This requires the amount of space in struct direct
 * without the d_name field, plus enough space for the name with a terminating
 * null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
 */
#define DIRSIZ(dp) \
    ((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

/*
 * Template for manipulating directories.
 * Should use struct direct's, but the name field
 * is MAXNAMLEN - 1, and this just won't do.
 */
struct dirtemplate {
	u_long	dot_ino;
	short	dot_reclen;
	short	dot_namlen;
	char	dot_name[4];		/* must be multiple of 4 */
	u_long	dotdot_ino;
	short	dotdot_reclen;
	short	dotdot_namlen;
	char	dotdot_name[4];		/* ditto */
};
#endif /* !_DIR_H_ */
Commit	Line	Data
169d8a33 RG	1	/*
	2	* Copyright (c) UNIX System Laboratories, Inc. All or some portions
	3	* of this file are derived from material licensed to the
	4	* University of California by American Telephone and Telegraph Co.
	5	* or UNIX System Laboratories, Inc. and are reproduced herein with
	6	* the permission of UNIX System Laboratories, Inc.
	7	*/
15637ed4 RG	8	/*
	9	* Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
	10	* All rights reserved.
	11	*
	12	* Redistribution and use in source and binary forms, with or without
	13	* modification, are permitted provided that the following conditions
	14	* are met:
	15	* 1. Redistributions of source code must retain the above copyright
	16	* notice, this list of conditions and the following disclaimer.
	17	* 2. Redistributions in binary form must reproduce the above copyright
	18	* notice, this list of conditions and the following disclaimer in the
	19	* documentation and/or other materials provided with the distribution.
	20	* 3. All advertising materials mentioning features or use of this software
	21	* must display the following acknowledgement:
	22	* This product includes software developed by the University of
	23	* California, Berkeley and its contributors.
	24	* 4. Neither the name of the University nor the names of its contributors
	25	* may be used to endorse or promote products derived from this software
	26	* without specific prior written permission.
	27	*
	28	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	29	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	30	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	31	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	32	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	33	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	34	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	35	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	36	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	37	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	38	* SUCH DAMAGE.
	39	*
1eb58e01	40	* from: @(#)dir.h 7.10 (Berkeley) 3/25/91
169d8a33	41	* $Id: dir.h,v 1.2 1993/10/16 18:17:37 rgrimes Exp $
15637ed4 RG	42	*/
	43
	44	#ifndef _DIR_H_
	45	#define _DIR_H_
	46
	47	/*
	48	* A directory consists of some number of blocks of DIRBLKSIZ
	49	* bytes, where DIRBLKSIZ is chosen such that it can be transferred
	50	* to disk in a single atomic operation (e.g. 512 bytes on most machines).
	51	*
	52	* Each DIRBLKSIZ byte block contains some number of directory entry
	53	* structures, which are of variable length. Each directory entry has
	54	* a struct direct at the front of it, containing its inode number,
	55	* the length of the entry, and the length of the name contained in
	56	* the entry. These are followed by the name padded to a 4 byte boundary
	57	* with null bytes. All names are guaranteed null terminated.
	58	* The maximum length of a name in a directory is MAXNAMLEN.
	59	*
	60	* The macro DIRSIZ(dp) gives the amount of space required to represent
	61	* a directory entry. Free space in a directory is represented by
	62	* entries which have dp->d_reclen > DIRSIZ(dp). All DIRBLKSIZ bytes
	63	* in a directory block are claimed by the directory entries. This
	64	* usually results in the last entry in a directory having a large
	65	* dp->d_reclen. When entries are deleted from a directory, the
	66	* space is returned to the previous entry in the same directory
	67	* block by increasing its dp->d_reclen. If the first entry of
	68	* a directory block is free, then its dp->d_ino is set to 0.
	69	* Entries other than the first in a directory do not normally have
	70	* dp->d_ino set to 0.
	71	*/
	72	#define DIRBLKSIZ DEV_BSIZE
	73	#define MAXNAMLEN 255
	74
	75	struct direct {
	76	u_long d_ino; /* inode number of entry */
	77	u_short d_reclen; /* length of this record */
	78	u_short d_namlen; /* length of string in d_name */
	79	char d_name[MAXNAMLEN + 1]; /* name with length <= MAXNAMLEN */
	80	};
	81
	82	/*
	83	* The DIRSIZ macro gives the minimum record length which will hold
	84	* the directory entry. This requires the amount of space in struct direct
	85	* without the d_name field, plus enough space for the name with a terminating
	86	* null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
	87	*/
	88	#define DIRSIZ(dp) \
	89	((sizeof (struct direct) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))
	90
	91	/*
	92	* Template for manipulating directories.
	93	* Should use struct direct's, but the name field
	94	* is MAXNAMLEN - 1, and this just won't do.
	95	*/
	96	struct dirtemplate {
	97	u_long dot_ino;
	98	short dot_reclen;
	99	short dot_namlen;
	100	char dot_name[4]; /* must be multiple of 4 */
	101	u_long dotdot_ino;
	102	short dotdot_reclen;
	103	short dotdot_namlen;
	104	char dotdot_name[4]; /* ditto */
	105	};
106	#endif /* !_DIR_H_ */